In reprocessing nuclear fuels using the PUREX process, containers and other equipment are exposed to corrosive flows containing nitric acid. It is therefore necessary to use a steel which has a high level of resistance to corrosion. It was found that high-alloy steels which in themselves are resistant to corrosion have a lower service life at their join which in most cases is a welded seam. The welding operation gives rise to thermal cracks and changes in structure in the welded seam, and such phenomena have an adverse effect on the corrosion performance of the welded seam, in comparison with the main material.